Drug & supplement interaction

Sorrel + Fexofenadine, Pseudoephedrine

Fexofenadine, Pseudoephedrine brand name: Allegra D.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Fexofenadine, Pseudoephedrine falls into 2 drug categories that Sorrel can interact with; the most serious is rated moderate. Sorrel might reduce the effectiveness of OATP substrates by reducing their absorption from the gut.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Sorrel and Fexofenadine, Pseudoephedrine

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Sorrel interacts with whole categories of medication. Fexofenadine, Pseudoephedrine falls into 2 of those categories, so it can interact with Sorrel in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

ORGANIC ANION-TRANSPORTING POLYPEPTIDE SUBSTRATES (OATP)

1 of 2

Why this applies to Fexofenadine, Pseudoephedrine

Fexofenadine, Pseudoephedrine falls under ORGANIC ANION-TRANSPORTING POLYPEPTIDE SUBSTRATES (OATP) — the group Sorrel interacts with.

Sorrel might reduce the effectiveness of OATP substrates by reducing their absorption from the gut.
In vitro research shows that sorrel inhibits OATP1A2. Theoretically it may inhibit other OATPs. The OATPs are expressed in the small intestine and liver and transport drugs into cells. Inhibition of OATP may reduce the bioavailability of oral drugs that are substrates of OATP.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist with Allegra-D and sorrel. The fexofenadine part of this combo needs a little transporter protein called OATP to get pulled out of your gut and into your bloodstream. Lab studies suggest sorrel can block that transporter, which could mean less fexofenadine actually gets absorbed. In plain terms, your allergy relief (the runny nose, sneezing, itchy eyes coverage) might not work quite as well.

That said, this is based only on test-tube research, not real people, so the effect may be small or even unnoticeable, especially with sorrel used as food. Concentrated sorrel supplements are more of a question mark. The pseudoephedrine half isn't really affected. If you use sorrel regularly, just mention it to your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Ahn JH, Kim J, Rehman NU, Kim HJ, Ahn MJ, Chung HJ. Effect of Rumex Acetosa Extract, a Herbal Drug, on the Absorption of Fexofenadine. Pharmaceutics. 2020;12(6):E547. PubMed
Moderate

FEXOFENADINE (Allegra)

2 of 2
Sorrel might reduce the effectiveness of fexofenadine by reducing its absorption from the gut.
In vitro research shows that an ethanol extract of sorrel inhibits organic anion-transporting polypeptide 1A2 (OATP1A2), which transports fexofenadine from the intestine into cells. In rats, concomitant administration of sorrel extract with fexofenadine reduces oral absorption of fexofenadine and the area under the plasma concentration-time curve (AUC).
Severity Moderate Likelihood Likely Evidence D

Well-controlled human studies have demonstrated the likely existence of this interaction.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist with Allegra-D: the fexofenadine half relies on a little gut transporter called OATP1A2 to get absorbed into your body. Lab and animal studies suggest sorrel may block that transporter, which could mean less fexofenadine actually makes it into your bloodstream. In plain terms, your allergy relief might not work as well, so you could still notice a runny nose, itchy eyes, or sneezing.

I want to be honest about the strength of this: it's based on test-tube and rat data, not real people, so we can't say for sure how much it matters for you. The pseudoephedrine part isn't really involved here. A sprinkle of sorrel in soup is unlikely to cause trouble, but concentrated supplements are the bigger question. If you're taking sorrel regularly, just run it by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Ahn JH, Kim J, Rehman NU, Kim HJ, Ahn MJ, Chung HJ. Effect of Rumex Acetosa Extract, a Herbal Drug, on the Absorption of Fexofenadine. Pharmaceutics. 2020;12(6):E547. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Sorrel Also Interacts With Other Medications

Sorrel has 168 moderate known drug interactions in our database — the Fexofenadine, Pseudoephedrine one above is among them. If you take anything else, check it against the full list below.

Moderate 168 No known interaction 2,662 (incl. Fexofenadine, Pseudoephedrine)
Taking anything else?

Check Another of Your Medications Against Sorrel

Covers the 2,830 medications we’ve checked against Sorrel. Pick one to open its full report.

From our Q&A

Questions About Sorrel or Fexofenadine, Pseudoephedrine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Sorrel or Fexofenadine, Pseudoephedrine, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Fexofenadine, Pseudoephedrine

This page covers Sorrel only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fexofenadine, Pseudoephedrine page lists 188 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Apple (major), Ephedra (major), Grapefruit (major) and Peyote (major).

By severity: 9 major · 140 moderate · 39 minor.

From our pharmacist’s overview on the Fexofenadine, Pseudoephedrine page

“The person reaching for Allegra D (fexofenadine with pseudoephedrine) is congested, itchy, and probably washing the tablet down with juice or coffee, which is exactly where the trouble starts. This combination deserves genuine care.”

Reviewed by 2 · Jul 18, 2026

Open the Fexofenadine, Pseudoephedrine interaction page

One more smart check

Taking Sorrel as Part of a Dietary Supplement Product? Check It for Interactions

We hold 224 real supplement products containing Sorrel, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Sorrel. Your product may carry other ingredients that interact with Fexofenadine, Pseudoephedrine too, on top of Sorrel — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Sorrel and Fexofenadine, Pseudoephedrine Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Sorrel
Top half

#437 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Fexofenadine, Pseudoephedrine
Top 10%

#149 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Sorrel

What is Sorrel?

Sorrel
  • Sinus and respiratory congestion
  • Digestive upset
  • Fever
  • Skin conditions and inflammation
  • Antioxidant support

Sorrel is a tangy, leafy herb used in cooking and traditional medicine, often for congestion, digestion, and inflammation. Solid human evidence for any health benefit is limited, and its high oxalate content means it should be used in moderation, especially by people prone to kidney stones.

Read the full Sorrel monograph & all interactions
Keep checking

Other Drugs & Sorrel

Browse every other medication we’ve checked against Sorrel — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
168Moderate
0Minor
2,661No known interaction
168 Moderate 2,661 No interaction
Moderate

168 interactions

Showing 60 of 168 moderate interactions — see all 168 on the Sorrel page.

No interaction 2,661 drugs checked — show the list

We also checked Sorrel against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,661 medications checked with no known interaction — see the full Sorrel list.

See the full Sorrel interactions page
See every supplement checked against Fexofenadine, Pseudoephedrine, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Sorrel monograph › Uses, safety, and every drug interaction in one place Fexofenadine, Pseudoephedrine supplement interactions › Every supplement checked against Fexofenadine, Pseudoephedrine, ranked by severity Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Sorrel and Fexofenadine, Pseudoephedrine Together: Common Questions

Can you take Sorrel with Fexofenadine, Pseudoephedrine?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 2 interactions listed for Sorrel and Fexofenadine, Pseudoephedrine?
Fexofenadine, Pseudoephedrine belongs to more than one drug category, and Sorrel interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Sorrel and Fexofenadine, Pseudoephedrine interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Fexofenadine, Pseudoephedrine and Sorrel?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.